Neo4j 如何设置节点属性以在计算其值时使用函数？

我试图向用户节点添加一个平均评级属性，并分配该值。 我可以通过下面的cql查询成功地获取用户ID和平均值

MATCH (n)-[r:RATES]->(m)
RETURN DISTINCT n.userid as userid, AVG(toFloat(r.rating)) as avgrating
ORDER BY n.userid

如何将平均值添加到n（用户）节点？ 我试过一次，但没有成功

MATCH p = (n)-[r:RATES]->(m)
FOREACH (n IN nodes(p)| SET n.avgrating = AVG(toFloat(r.rating)))

还有一套

MATCH (n)-[r:RATES]->(m)
SET n.avgrating = AVG(toFloat(r.rating))
RETURN n.userid, n.avgrating)
ORDER BY n.userid;

MATCH (p:Person)-[r:RATES]->()
WITH p, AVG(r.rating) AS avg
SET p.avg_rating = avg